《趣味科普學英語》介紹
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導讀
想像一下，未來人類會不會真的有可能移居地球以外的星球？
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中英文文本
人類文明能遍布銀河系嗎
Could human civilization eventually spread across the whole Milky Way galaxy?
我們能在這個小小的藍色星球之外的
Could we move beyond our small blue planet
廣袤星系建立殖民地嗎
to establish colonies in the multitude of star systems out there?
這個問題還挺嚇人的
This question’s a pretty daunting one.
銀河系有3000億顆恆星左右
There are around 300 billion stars in the galaxy,
從一邊到另一邊的距離是160000光年
which is about 160,000 light-years across.
現在為止我們就發送了一艘宇宙飛船到太陽系外
So far we』ve sent a single spacecraft outside our solar system,
以0.006%光速緩慢前行
trudging along at 0.006% of the speed of light.
以那個速度 得花不止25億年
At that rate, it would take over 2.5 billion years
才能橫跨一個星系
just to get from one end of the galaxy to the other.
然後就有了這個人類生存的問題
And then there’s the question of human survival.
恆星間的距離簡直大無邊際
The gulf between stars is simply enormous.
在多數星球上我們都不能持續生存
We couldn’t live sustainably on most planets,
而且我們需要很多資源才能存活下來
and we require a lot of resources to stay alive.
然而幾十年前 學者發現從理論角度
And yet, decades ago, scholars found that it’s theoretically possible
在銀河系傳播人類文明不僅是可行的
to not just spread human civilization across the galaxy,
而且還能很快實現
but to do so quite quickly,
還不違背現有的物理定律
without breaking any known laws of physics.
這個想法源於一名叫約翰·馮·諾依曼的數學家的研究
Their idea is based on the work of a mathematician named John von Neumann,
他在紙上設計了一臺能進行自動複製和創造新一代的機器
who designed on paper machines that could self-replicate
他在紙上設計了一臺能進行自動複製和創造新一代的機器
and create new generations of themselves.
後來這些機器被稱為馮·諾依曼機器
These would later come to be known as von Neumann machines.
在太空探索的背景下
In the context of space exploration,
馮·諾依曼機器可以建在地球上
von Neumann machines could be built on Earth
然後發射進太空太空中
and launched into space.
這種自給機器會在遙遠的星球著陸
There, the self-sufficient machines would land on distant planets.
然後開採可用資源、
They would then mine the available resources and harvest energy,
搜集能量進行自我複製
build replicas of themselves,
把複製的機器發射到最近的星球
launch those to the nearest planets,
然後不斷循環這個過程
and continue the cycle.
最後結果就是無數探測器
The result is the creation of millions of probes
像水裡的一點墨水一樣不斷向外在宇宙中蔓延
spreading outwards into the universe like a drop of ink in a fishbowl.
學者進行計算之後發現 一臺馮·諾依曼機器
Scholars crunched the numbers and found that a single von Neumann machine
以5%光速飛行
traveling at 5% of the speed of light
要花400萬年才能通過不斷複製穿越銀河系
should be able to replicate throughout our galaxy in 4 million years or less.
聽起來時間很長
That may sound like a long time,
但想到140億歲高齡的宇宙
but when you consider that our universe is 14 billion years old,
從宇宙尺度看來已經非常快了
on a cosmic scale, it’s incredibly fast –
也就是一整年裡的兩個半小時
the equivalent of about 2.5 hours in an entire year.
造一臺馮·諾依曼機器需要幾項目前沒有的新技術
Creating von Neumann machines would require a few technologies
造一臺馮·諾依曼機器需要幾項目前沒有的新技術
we don’t have yet,
包括先進的人工智慧
including advanced artificial intelligence,
微型化科技
miniaturization,
更好的推進系統
and better propulsion systems.
如果想運用這些技術把人類送進銀河系
If we wanted to use them to spread actual humans throughout the galaxy,
我們還得需要另一項技術性飛躍
we would need yet another technological leap –
通過原始元素和基因信息來人為造出生物有機體和生物機體
the ability to artificially grow biological organisms and bodies
通過原始元素和基因信息來人為造出生物有機體和生物機體
using raw elements and genetic information.
不管怎麼說 如果過去10億年間
Regardless, if in the last billion years
有外星文明造出了類似的機器
an alien civilization created such a machine
通過不斷複製的方式向我們駛來
and set it multiplying its way toward us,
我們的銀河系應該已經到處都是這些機器了
our galaxy would be swarming with them by now.
但是那些機器在哪兒呢
So then where are all these machines?
一些天文學家 比如卡爾·薩根
Some astronomers, like Carl Sagan,
說聰明的外星人不可能建造自我複製機器
say that intelligent aliens wouldn’t build self-replicating machines at all.
這些機器會在橫衝直撞後失去控制
They might hurtle out of control,
為了實現自我複製把星球洗劫一空
scavenging planets to their cores in order to keep replicating.
另外一些人認為這種機器不存在是因為
Others take the machines absence as proof
根本不存在智慧的外星文明
that intelligent alien civilizations don’t exist,
或者在他們發展出必要科技前就已經滅絕了
or that they go extinct before they can develop the necessary technologies.
但這些想法並不妨礙人類想像 如果存在外星文明
But all this hasn’t stopped people from imagining what it would be like
將是怎樣一番景象
if they were out there.
科幻小說作家大衛·布林
Science fiction author David Brin
描寫了一個存在許多不同的馮·諾依曼機器並同時擴散的宇宙
writes about a universe in which many different von Neumann machines exist
描寫了一個存在許多不同的馮·諾依曼機器並同時擴散的宇宙
and proliferate simultaneously.
一些機器跟年輕文明打招呼
Some are designed to greet young civilizations,
另一些則定位年輕文明 並且在年輕文明成為威脅前將其摧毀實際上
others to locate and destroy them before they become a threat.
布林的小說「Lungfish」裡面
In fact, in Brin’s story 「Lungfish,」
一些馮·諾依曼機器正密切關注著地球
some von Neumann machines are keeping a close watch over the Earth right now,
等我們成熟到一定階段後
waiting for us to reach a certain level of sophistication
他們才採取行動目前
before they make their move.
我們有的只是好奇心和理論
For now, all we have is curiosity and theory.
但下次你仰望夜空時
But the next time you look at the night sky,
想像無數自我複製的機器
consider that billions of self-replicating machines
正在銀河系的恆星間穿梭
could be advancing between stars in our galaxy right now.
如果它們存在 最後一定會降臨地球
If they exist, one of them will eventually land on Earth,
也許 它們已經到地球
or maybe, just maybe, they’re already here.